1. Field of the Invention
The present invention relates to an image recording apparatus that, calculates an amount of ink waste used for, e.g., cleaning processing based on a temperature of an ink utilized for image recording, and to an ink amount calculation method for this image recording apparatus.
2. Description of the Related Art
In general, an image recording apparatus which ejects ink of a single color or a plurality of colors onto a recording medium to record an image (which will be referred to as a printer hereinafter) is known. As recording heads of this printer, there are a scanning (serial) type recording head which reciprocates for scanning in a width direction (a direction orthogonal to a carrying direction) of a recording medium to eject ink and a fixed recording head which oppositely carries a recording medium to eject ink.
In ink supply, a size and a weight of the scanning type recording head are reduced since this recording head is arranged on a carriage to be moved, and a scheme of replacing an ink cartridge having a small-capacity ink chamber provided therein is general. On the other hand, in the fixed recording head, a replaceable replenishment ink tank (or a main ink tank) having a larger capacity than that of the ink cartridge of the scanning type recording head is provided.
A user keeps up this printer and carries out regular maintenance (e.g., ink replenishment, cleaning of the recording head, or a measure for a jam error) except, e.g., a countermeasure against a failure. The user replaces the main ink tank based on notification (e.g., an ink replenishment instruction or warning of a remaining ink amount) from the printer. Therefore, accurately detecting a remaining ink amount is important when setting a timing for replacement. When a remaining ink amount cannot be accurately detected, for example, the user is urged to replace the ink tank even though the remaining ink amount is sufficient for recording, and replacement is eventually performed, which is not economical. Contrarily, the user is not informed of replacement of the ink tank even though the ink has run out, and a recording failure or waste of a recording medium occurs due to non-ejection of the ink.
In the printer, there are roughly two types of operations that consume ink. First, there is ejection of ink when recording an image. Second, there is ejection of ink during maintenance, which is carried out to maintain ejection performance during recording. Ejection of ink during maintenance is carried out to eliminate, e.g., paper powder or eject ink having high viscosity. This is an operation of ejecting ink from nozzles as required or at regular intervals and expelling air bubbles or foreign particles to restore or preservation ink ejection performance.
A remaining ink amount in the main ink tank cannot be accurately detected unless an ink consumption amount in these ink ejection operations is accurately detected. In these types of amounts, the ink ejection amount used for image recording can be accurately obtained to some extent based on, e.g., the number of times of ejection from nozzles or a particle diameter of an ink drop from the nozzles. On the other hand, as to the ink ejection amount in maintenance processing, since the ink may be ejected when the nozzles are not driven (due to suction of the ink from the outside of the recording head or application of a pressure from the inside of the recording head), an ejected ink waste amount must be additionally detected.
The ink waste amount ejected in the maintenance processing is greatly dependent on an ink temperature during ejection, i.e., a temperature near the nozzles. This suggests that ink ejection characteristics in the recording head greatly vary depending on an ink temperature as well as that an ink amount ejected from the nozzles greatly varies depending on an ink temperature. Therefore, for example, as disclosed in JP-A 2006-199021 (KOKAI), using a temperature gauge to manage an ink temperature is suggested. An ink waste amount ejected in maintenance is greatly dependent on an ink temperature during ejection, i.e., a temperature near the nozzles. If an ink waste amount can be accurately calculated, a remaining ink amount in the ink tank can be accurately detected.